Taxes on an apartment gifted to my mom who is a foreign citizen

If you are a US person subject to US tax law (that means a citizen, green card holder, or resident alien who passes the substantial presence test) then you must report gifts of more than $16,000 per year per person using form 709.  However, no gift tax is actually owed unless your total lifetime gifts is more than $12 million.  Form 709 is used to track your large gifts against your lifetime total.

Form 709 has the same deadline as a regular tax return (April 15) but is filed separately from your tax return.  Turbotax does not prepare this form, you will have to do it yourself.

https://www.irs.gov/forms-pubs/about-form-709